| 1 | #ifndef _LIB_RING_BUFFER_VFS_H |
| 2 | #define _LIB_RING_BUFFER_VFS_H |
| 3 | |
| 4 | /* |
| 5 | * lib/ringbuffer/vfs.h |
| 6 | * |
| 7 | * Wait-free ring buffer VFS file operations. |
| 8 | * |
| 9 | * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 10 | * |
| 11 | * This library is free software; you can redistribute it and/or |
| 12 | * modify it under the terms of the GNU Lesser General Public |
| 13 | * License as published by the Free Software Foundation; only |
| 14 | * version 2.1 of the License. |
| 15 | * |
| 16 | * This library is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 19 | * Lesser General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU Lesser General Public |
| 22 | * License along with this library; if not, write to the Free Software |
| 23 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 24 | * |
| 25 | * Author: |
| 26 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 27 | */ |
| 28 | |
| 29 | #include <linux/fs.h> |
| 30 | #include <linux/poll.h> |
| 31 | |
| 32 | /* VFS API */ |
| 33 | |
| 34 | extern const struct file_operations lib_ring_buffer_file_operations; |
| 35 | |
| 36 | /* |
| 37 | * Internal file operations. |
| 38 | */ |
| 39 | |
| 40 | struct lib_ring_buffer; |
| 41 | |
| 42 | int lib_ring_buffer_open(struct inode *inode, struct file *file, |
| 43 | struct lib_ring_buffer *buf); |
| 44 | int lib_ring_buffer_release(struct inode *inode, struct file *file, |
| 45 | struct lib_ring_buffer *buf); |
| 46 | unsigned int lib_ring_buffer_poll(struct file *filp, poll_table *wait, |
| 47 | struct lib_ring_buffer *buf); |
| 48 | ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos, |
| 49 | struct pipe_inode_info *pipe, size_t len, |
| 50 | unsigned int flags, struct lib_ring_buffer *buf); |
| 51 | int lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma, |
| 52 | struct lib_ring_buffer *buf); |
| 53 | |
| 54 | /* Ring Buffer ioctl() and ioctl numbers */ |
| 55 | long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd, |
| 56 | unsigned long arg, struct lib_ring_buffer *buf); |
| 57 | #ifdef CONFIG_COMPAT |
| 58 | long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd, |
| 59 | unsigned long arg, struct lib_ring_buffer *buf); |
| 60 | #endif |
| 61 | |
| 62 | ssize_t vfs_lib_ring_buffer_file_splice_read(struct file *in, loff_t *ppos, |
| 63 | struct pipe_inode_info *pipe, size_t len, unsigned int flags); |
| 64 | loff_t vfs_lib_ring_buffer_no_llseek(struct file *file, loff_t offset, |
| 65 | int origin); |
| 66 | int vfs_lib_ring_buffer_mmap(struct file *filp, struct vm_area_struct *vma); |
| 67 | ssize_t vfs_lib_ring_buffer_splice_read(struct file *in, loff_t *ppos, |
| 68 | struct pipe_inode_info *pipe, size_t len, |
| 69 | unsigned int flags); |
| 70 | |
| 71 | /* |
| 72 | * Use RING_BUFFER_GET_NEXT_SUBBUF / RING_BUFFER_PUT_NEXT_SUBBUF to read and |
| 73 | * consume sub-buffers sequentially. |
| 74 | * |
| 75 | * Reading sub-buffers without consuming them can be performed with: |
| 76 | * |
| 77 | * RING_BUFFER_SNAPSHOT |
| 78 | * RING_BUFFER_SNAPSHOT_GET_CONSUMED |
| 79 | * RING_BUFFER_SNAPSHOT_GET_PRODUCED |
| 80 | * |
| 81 | * to get the offset range to consume, and then by passing each sub-buffer |
| 82 | * offset to RING_BUFFER_GET_SUBBUF, read the sub-buffer, and then release it |
| 83 | * with RING_BUFFER_PUT_SUBBUF. |
| 84 | * |
| 85 | * Note that the "snapshot" API can be used to read the sub-buffer in reverse |
| 86 | * order, which is useful for flight recorder snapshots. |
| 87 | */ |
| 88 | |
| 89 | /* Get a snapshot of the current ring buffer producer and consumer positions */ |
| 90 | #define RING_BUFFER_SNAPSHOT _IO(0xF6, 0x00) |
| 91 | /* Get the consumer position (iteration start) */ |
| 92 | #define RING_BUFFER_SNAPSHOT_GET_CONSUMED _IOR(0xF6, 0x01, unsigned long) |
| 93 | /* Get the producer position (iteration end) */ |
| 94 | #define RING_BUFFER_SNAPSHOT_GET_PRODUCED _IOR(0xF6, 0x02, unsigned long) |
| 95 | /* Get exclusive read access to the specified sub-buffer position */ |
| 96 | #define RING_BUFFER_GET_SUBBUF _IOW(0xF6, 0x03, unsigned long) |
| 97 | /* Release exclusive sub-buffer access */ |
| 98 | #define RING_BUFFER_PUT_SUBBUF _IO(0xF6, 0x04) |
| 99 | |
| 100 | /* Get exclusive read access to the next sub-buffer that can be read. */ |
| 101 | #define RING_BUFFER_GET_NEXT_SUBBUF _IO(0xF6, 0x05) |
| 102 | /* Release exclusive sub-buffer access, move consumer forward. */ |
| 103 | #define RING_BUFFER_PUT_NEXT_SUBBUF _IO(0xF6, 0x06) |
| 104 | /* returns the size of the current sub-buffer, without padding (for mmap). */ |
| 105 | #define RING_BUFFER_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, unsigned long) |
| 106 | /* returns the size of the current sub-buffer, with padding (for splice). */ |
| 107 | #define RING_BUFFER_GET_PADDED_SUBBUF_SIZE _IOR(0xF6, 0x08, unsigned long) |
| 108 | /* returns the maximum size for sub-buffers. */ |
| 109 | #define RING_BUFFER_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, unsigned long) |
| 110 | /* returns the length to mmap. */ |
| 111 | #define RING_BUFFER_GET_MMAP_LEN _IOR(0xF6, 0x0A, unsigned long) |
| 112 | /* returns the offset of the subbuffer belonging to the mmap reader. */ |
| 113 | #define RING_BUFFER_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, unsigned long) |
| 114 | /* Flush the current sub-buffer, if non-empty. */ |
| 115 | #define RING_BUFFER_FLUSH _IO(0xF6, 0x0C) |
| 116 | /* Get the current version of the metadata cache (after a get_next). */ |
| 117 | #define RING_BUFFER_GET_METADATA_VERSION _IOR(0xF6, 0x0D, uint64_t) |
| 118 | /* |
| 119 | * Get a snapshot of the current ring buffer producer and consumer positions, |
| 120 | * regardless of whether or not the two positions are contained within the same |
| 121 | * sub-buffer. |
| 122 | */ |
| 123 | #define RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS _IO(0xF6, 0x0E) |
| 124 | /* Flush the current sub-buffer, even if empty. */ |
| 125 | #define RING_BUFFER_FLUSH_EMPTY _IO(0xF6, 0x0F) |
| 126 | |
| 127 | #ifdef CONFIG_COMPAT |
| 128 | /* Get a snapshot of the current ring buffer producer and consumer positions */ |
| 129 | #define RING_BUFFER_COMPAT_SNAPSHOT RING_BUFFER_SNAPSHOT |
| 130 | /* Get the consumer position (iteration start) */ |
| 131 | #define RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED \ |
| 132 | _IOR(0xF6, 0x01, compat_ulong_t) |
| 133 | /* Get the producer position (iteration end) */ |
| 134 | #define RING_BUFFER_COMPAT_SNAPSHOT_GET_PRODUCED \ |
| 135 | _IOR(0xF6, 0x02, compat_ulong_t) |
| 136 | /* Get exclusive read access to the specified sub-buffer position */ |
| 137 | #define RING_BUFFER_COMPAT_GET_SUBBUF _IOW(0xF6, 0x03, compat_ulong_t) |
| 138 | /* Release exclusive sub-buffer access */ |
| 139 | #define RING_BUFFER_COMPAT_PUT_SUBBUF RING_BUFFER_PUT_SUBBUF |
| 140 | |
| 141 | /* Get exclusive read access to the next sub-buffer that can be read. */ |
| 142 | #define RING_BUFFER_COMPAT_GET_NEXT_SUBBUF RING_BUFFER_GET_NEXT_SUBBUF |
| 143 | /* Release exclusive sub-buffer access, move consumer forward. */ |
| 144 | #define RING_BUFFER_COMPAT_PUT_NEXT_SUBBUF RING_BUFFER_PUT_NEXT_SUBBUF |
| 145 | /* returns the size of the current sub-buffer, without padding (for mmap). */ |
| 146 | #define RING_BUFFER_COMPAT_GET_SUBBUF_SIZE _IOR(0xF6, 0x07, compat_ulong_t) |
| 147 | /* returns the size of the current sub-buffer, with padding (for splice). */ |
| 148 | #define RING_BUFFER_COMPAT_GET_PADDED_SUBBUF_SIZE \ |
| 149 | _IOR(0xF6, 0x08, compat_ulong_t) |
| 150 | /* returns the maximum size for sub-buffers. */ |
| 151 | #define RING_BUFFER_COMPAT_GET_MAX_SUBBUF_SIZE _IOR(0xF6, 0x09, compat_ulong_t) |
| 152 | /* returns the length to mmap. */ |
| 153 | #define RING_BUFFER_COMPAT_GET_MMAP_LEN _IOR(0xF6, 0x0A, compat_ulong_t) |
| 154 | /* returns the offset of the subbuffer belonging to the mmap reader. */ |
| 155 | #define RING_BUFFER_COMPAT_GET_MMAP_READ_OFFSET _IOR(0xF6, 0x0B, compat_ulong_t) |
| 156 | /* Flush the current sub-buffer, if non-empty. */ |
| 157 | #define RING_BUFFER_COMPAT_FLUSH RING_BUFFER_FLUSH |
| 158 | /* Get the current version of the metadata cache (after a get_next). */ |
| 159 | #define RING_BUFFER_COMPAT_GET_METADATA_VERSION RING_BUFFER_GET_METADATA_VERSION |
| 160 | /* |
| 161 | * Get a snapshot of the current ring buffer producer and consumer positions, |
| 162 | * regardless of whether or not the two positions are contained within the same |
| 163 | * sub-buffer. |
| 164 | */ |
| 165 | #define RING_BUFFER_COMPAT_SNAPSHOT_SAMPLE_POSITIONS \ |
| 166 | RING_BUFFER_SNAPSHOT_SAMPLE_POSITIONS |
| 167 | /* Flush the current sub-buffer, even if empty. */ |
| 168 | #define RING_BUFFER_COMPAT_FLUSH_EMPTY \ |
| 169 | RING_BUFFER_FLUSH_EMPTY |
| 170 | #endif /* CONFIG_COMPAT */ |
| 171 | |
| 172 | #endif /* _LIB_RING_BUFFER_VFS_H */ |